Stone shaping device



April 23, 1935. E. c. SMITH 1,998,642

STONE SHAPING DEVICE 0 Filed Dec. 16, 1932 v fa ward Jan/7%.,

b mm

A TTORNEY.

INVENTOR:

Patented Apr. 23, 1935 UNITED 1,998,642 STONE SHAPING fiEVIGl] Edwardc.,;smiti1, Santa; Barbara, Calif Application member 16, 1932, SerialNo; 647,515 mm; (01. 51-101 invention relates to means for shapingstones and refers particularly to a jig used in convide a simple andinexpensive jig, by means of whichprecious or semiprecious stones may beground to any desired perimetric angular outliiie; A further object-isthe provision of a jig by the use of which the contours of a pluralityof stones may successively be ground to the same shape and size. Anotherobject is to provide a jig furnished with a plurality. of gem supportsand shaped successitely to receive such supports for the purpose ofgrinding the gems carried by the supports to the same shape.

With these objects in view, the invention consists in the combinationsand important features hereinafter fully described and: illustrated inthe appended drawing, of which:

Fig. 1 is a perspective view of a gem shaping jig embodying theinvention, 5

Fig; 2 is an end elevation of the'device, and

Fig. 3'illustrates the gem support of the invention, as it appearsremoved from the jig.

The structure of my invention is mounted one base H, which may be placedon the table or bench on which a grinding head is mounted, as usual inpractice, in close proximity to the grind ing wheel IQ, of such machine.

The jig is made with vertically alined slots l3, inwhich' a gem supportis shown axially seated to rotate.- This support comprises a member 2,into which a stem 9 is inserted for longitudinal ad'- justment. A setscrew ll; threaded into a boss mof'the member 2, servesto maintain thestem in adjusted position. To the top of the stem ls rigidly secured aplate 8,'upon which a rough gem 'lTiSShO-Wfl placed, andithis gem istemporarily held fastened to theplate by a; suitable cement.

From this brief description, it is seen that the jigimay be pushedtoward the wheel and the stem adjusted. vertically in the support untilthe edge of the gem touches the periphery of the wheel,

whereupon the gemsupport is manually rotated in the slots by twirlingits cylindrical portion '4 between. the thumb and index finger. In thismanner, a circular contour is given the gem, the angle of which dependsupon the height to which the gem support is adjusted. It is not,however, always desired to produce circular gems, but other shapes maybe required. For the purpose of obtaining some particular perimetricoutline, I mount on the gem support a pair of patterns, or

templets i, for contact with alined, fixed gages l8 of the jig frame.The contour of these temple't's is made in the shape of thefinished gemand, when the support is" rotated as aforesaid, bringing slight pressureto bear against the gages l8, such shape is quickly reproduced on thegem. The radial distance of the jig from the wheel center determines thesize to which the gem may be ground.-

The gem: support is withdrawn from the" frame whenthe grinding operationis finished and may then be replaced by other-supports on which gems,to. be cut to the same size and shapeghaye been previously cemented. Theoperation iscontinued in. this maner until all identically shaped gemsare finished. Or, instead of a whole new sup port, it may be preferredmerely to exchange: stems 9,.ex'cept that, in such case, care must betaken to adjust each stem to the sameheightin the support. I- wish itunderstood, also, that more tharr one set of vertically alinedslots maybe provided for simultaneous grinding of a plurality of gems. More thanone support may be rotated at the same time by the fingers and palm ofone hand, or mechanical devices may be introduced for this purpose. 7

The structure of the jig comprises, a pair of bifurcated standards it,rigidly mounted on the jig base H; In the groovesof these standards isseated a rectangular jig frame consisting of. 1011' gitudinal membersl2,:in which the'afdrenamed alined slots i3- are sunk, and these membersare combined by end plates Hi. Vertical fianges'; or cars it extend incontinued alinemen-t in opposite directions from theframe ends" to restin the grooves of the supports [6. Series of set screws 2i, seatedinthese-standards, serve-to clamp the jig frame. firmly, in position; allas clearly shown in the drawing.

This type of mounting permits of; sliding the jig frame longitudinallyin the-standards'for the purpose of usingup'the full width of the faceof the grinding wheel. Itmay be suggested here, that the jig: might bemoved bodily for such purpose. But it must be remembered that thegrindingoperation is very delicate and the jig" relatively very heavy:Once it is set in alinement with the wheel, it remains in this positionuntil gems of other sizes are to be shaped. For this reason, movement ofthe jig as a whole, would not be practical, but by slightly looseningthe set screws on one side, the jig frame may conveniently be adjustedlengthwise.

By means of these screws it is also possible, within certain limits,,totilt the jig frame, as indi-- cated in Fig. 2, and this is necessarywhere the wheel is so close to the machine bed that it is not possible,with a vertically positioned gem support, to get far enough under thewheel to obtain the required angle.

In cases where great quantities of stones, of the same shape or size areto be ground, it may be preferred to clamp the jig rigidly on the tableor bench on which the grinding head is bolted, but it is important thatthe jig should be complete and self contained, so that it may readily bemoved to any required position or to any grinding wheel on the bench.

For convenience in assembling the gem support, the member 2 is shownmade with a raised band, or collar 3, see also Fig. 3, against which theupper templet I is first seated. The cylindrical body portion 4 is thenpushed on to the member, followed by the lower templet I, and a threadedsleeve 5 is thereupon caused to engage the thread' ed end 6, of themember 2, to clamp all the parts firmly together. The member 2 and thestem 9 are shown squared in order to prevent relative rotation, but anyother suitable shape may be substituted.

To the underside of the lower frame member [2 is shown attached abracket 2D, on which the lower end of the gem support may be rested inorder to raise the templets free of the frame and thereby to preventunnecessary wear on the adjacent templet and frame surfaces.

Delicacy of touch, and not great precision, is the prerequisite in gemshaping, and this I attain by the use of my very simple and inexpensivejig, constructed substantially as above described.

I claim:

l. A gem grinding fixture comprising, a base, a frame slidable thereon,a telescoping gem support insertable and manually rotatable in recessesof said frame, said support having a head for holding a gem to beground, means for locking the telescoping support portions together,gages on said frame, and templets mountable on the support to engagesaid gages.

2. In combination with a grinding machine, an independent fixture havinga flat base seatable on the table of said machine, a frame slidable onsaid base and made with perpendicularly alined recesses, and a gemcarrying holder manually insertable and rotatable in said recesses tobring a gem carried by said holder into contact with said wheel.

3. In combination with a grinding wheel, an independent fixture having abase, a frame slidable on said base and made with perpendicularly alinedrecesses, a gem carrying holder manually insertable and rotatable insaid recesses to bring a gem carried by said holder into contact withsaid wheel, gage stops on the frame, and templets mountable on saidholder for engagement with the gage stops of the frame for controllingthe perimetric shape to be ground.

4. A fixture placeable adjacent a grinding wheel and freely movablerelative to said wheel, a frame longitudinally slidable on the base andmade with perpendicularly alined recesses, an axially adjustable gemcarrier manually insertable and rotatable in said recesses to bring agem carried by the carrier into contact with said Wheel, alined agestops on the frame, and templets mountable on said carrier forengagement with said gage stops to control the perimetric shape to beground.

5. A fixture comprising, a base, a frame longitudinally slidable on saidbase, and means for clamping the frame in adjusted position on the base,in combination with a gem carrier comprising a cylindrical bodylaterally insertable and rotatable in vertically alined recesses of saidframe, a gem holder axially slidable in said body and terminating in ahead for receiving a gem to be ground, means for locking said gem holderin adjusted position in said body, vertically alined ases on said frame,and templets mountable on said body for engagement with said gages todetermine the perimetric shape to be ground.

6. For use on a grinding machine, a gem holding jig comprising, aframe'seatable on the table of such machine and having vertically alinedslots, a post vertically seatable and manually rotatable in thevertically alined slots of said frame, said post terminating at the topin a head on which a stone may be held seated by means of a binder,gages on said frame, and templets on the post for engagement with saidgages to determine the contour of the stone to be ground.

7. The combination with a grinding machine, of a jig seatable on themachine table comprising, a slotted frame, a telescoping post verticallyseatable and manually rotatable in the slots of the jig frame, ,saidpost being fitted on top to receive a gem to be ground, means forlocking the telescoping members of said post when vertically adjusted,templets on the post, and gages engageable by said templets to determinethe contour of the gem.

8. The combination with a grinding wheel, of a jig made with verticallyalined slots in the side, a post manually seatable and rotatable in saidslots, and interchangeable gem supports axially seatable in said post,means for locking each support in position in the post, each supportbeing shaped on top to receive a. gem to be ground, and means mountableon the post for engagement with the frame for determining the shape tobe ground as the post is manually rotated in the slots.

9. A gem grinding fixture comprising, a flat base, bifurcated standardson said base, a frame freely seatable in the bifurcations of saidstandards and made with alined recesses, means for clamping the frame inadjusted position within said bifurcations, and gem supporting meansmanually insertable and rotatable in the frame recesses.

10. A gem grinding fixture comprising, a flat base, bifurcated standardson said base, a rectangular boxshaped recessed frame made with endplates seatable in said bifurcations for lengthwise and crosswiseadjustment, clamping memhere in said standards for locking the frame inadjusted position, and gem supporting means seatable in the recesses ofsaid frame.

EDWARD C. SMITH.

